Lighting systems (such as headlights) are well-known and are used in a wide variety of applications, including automotive applications, and include one or more projector apparatus for emitting one or more distinct light patterns. For example, headlamps may be capable of emitting light in a low-beam pattern/mode in which light is generally emitted below the horizon, and a high beam pattern/mode in which light is generally emitted above and below the horizon.
A known type of automotive headlamps includes adaptive driving beam (ADB) headlamp systems. ADB headlamp systems are a long-range forward visibility beam that adapt to the presence of opposing and preceding vehicles by modifying portions of its beam pattern to avoid glare above lower beam photometry levels to the drivers of opposing and preceding vehicles. Since the 1960's, studies based on surveys throughout the United States have shown that drivers even in “open road” situations (neither following nor meeting another vehicles), switched their headlights to high beam mode too infrequently, and thus do not take advantage of the longer-range visibility that high beam offers. For example, a study by the University of Michigan Transportation Research Institute (UMTRI-2008-48, October 2008) reported average usage data on U.S. passenger vehicles that showed high beam usage at only about a tenth of low beam usage, with low beam at about 97 hours/year but high beam usage at only 9.8 hours/year. The automatic ADB offers a convenient system that could result in increased safety-beneficial upper beam use.
One embodiment of a known ADB headlamp system is generally illustrated in FIGS. 1-2. In particular, FIG. 1 is a block diagram showing schematically the structure of a prior art ADB headlamp system 1 and FIG. 2 is a schematic illustration showing the prior art ADB headlamp system 1 installed in a vehicle 2. The prior art ADB headlamp system 1 includes a headlamp 3, a vehicle on-board camera 4, and an ADB controller 5 electrically coupled to each other by way of a vehicle CAN-bus, LIN-bus, or similar vehicle bus (hereinafter generally referred to as CAN-bus 6). Other vehicle sensors/controllers 7 (such as, but not limited to, an electronic control unit (ECU), engine control module (ECM), sensors, and/or the like) may also be electrically coupled to the CAN-bus 6.
Known vehicle on-board camera 4 includes camera housing 8 configured to be attached within the cabin 9 of vehicle 2, conventionally proximate windshield 23 and/or rear view mirror 11 of vehicle 2. The vehicle on-board camera 4 is configured to generate an image based on received light 12 and to transmit the captured image to ADB controller 5 by way of a camera interface 10 electrically coupled to CAN-bus 6. ADB controller 5 receives the image captured by vehicle on-board camera 4, detects an object within the image, determines the position of the detected object within a beam pattern 13 generated by the headlamp 3, and generates one or more control signals that are transmitted to headlamp 3 across CAN-bus 6.
The headlamp 3 includes a headlamp housing 14 configured to be attached to a headlamp cavity 15 of the vehicle 2 (e.g., proximate the front 16 of the vehicle 2). The headlamp 3 also includes one or more light sources (such as light emitting diodes LEDs) and optics 17 configured to emit light in one or more patterns 13 (such as a high-beam mode as discussed above). A headlamp interface 18 receives the control signals from the ADB controller 5 across the CAN-bus 6 and is configured to control the driver circuitry 19 to selectively illuminate one or more LEDs/optics 17 to change the beam pattern 13 based on the position of the detected object relative to the beam pattern 13 and/or headlamp 3. Examples of known headlamp systems may be found, for example, in US Pat. Pub. Nos. 2009/0279317 (Tatara), 2009/0141513 (Kim); 2001/0019486 (Thominet); 2007/0002571 (Cejnek); 2003/0137849 (Alden); and 2015/0042225 (Fukayama), as well as U.S. Pat. No. 9,738,214 (Nakatani); U.S. Pat. No. 9,140,424 (Mochizuki); and U.S. Pat. No. 8,729,803 (Yamazaki).
While the known ADB headlamp systems 1 are generally effective, they suffer from several disadvantages. For example, the on-board vehicle camera 4, ADB controller 5, and headlamp 3 are electrically coupled by way of the vehicle CAN-bus 6. As a result, the known ADB headlamp systems 1 cannot be easily retrofitted into existing vehicles 2 unless the vehicle CAN-bus 6 was originally designed for an ADB headlamp system 1. In addition, the on-board vehicle camera 4 and the headlamp 3 are not mechanically connected and need to be physically aligned to each other and the vehicle 2 after the ADB headlamp system 1 has been installed in the vehicle 2. As a result, the ADB controller 5 cannot be calibrated until after the ADB headlamp system 1 has been installed in the vehicle 2.
Because the ADB controller 5 cannot be calibrated until after the ADB headlamp system 1 has been installed in the vehicle 2, the known ADB headlamp system 1 must be calibrated by the vehicle manufacturer. In particular, the known methods of calibrating ADB controllers 5 require the vehicle 2 to be removed from the main vehicle assembly line and transported into a calibration area after the ADB headlamp system 1 has been installed in the vehicle 2. Once the vehicle 2 is in the calibration area, subsets of the LEDs/optics 17 of the headlamp 3 may be selectively illuminated, images of the illumination region associated with each subset of LEDs/optics 17 may be captured, and the pixel boundaries of the illumination regions associated with each of the subset of LEDs/optics 17 may be determined. The position of the on-board vehicle camera 4 relative to the headlamp 3 and the vehicle 2 may then be precisely aligned.
As a result, the known calibration method requires additional space in the manufacturing facility, thereby increasing manufacturing costs of the vehicle 2. Moreover, since the vehicle 2 must be removed from the main vehicle assembly line and transported into a calibration area, the length, complexity, and manufacturing costs of the vehicle 2 is increased. In addition, the known calibration methods require the precise physical alignment of the on-board vehicle camera 4 relative to the headlamp 3 and the vehicle 2, thereby further increasing the length, complexity, and manufacturing costs of the vehicle 2.